1. Field of the Invention
The present invention relates to an arrangement of ventilation ducts in which bag filters or similar bag-shaped filters made of filter gauze are mounted with the open end portions sealingly attached to the walls of the ducts. A balancing of the air flow in the ducts of the plant is achieved by required individual throttling of the air throughflow capacity of the filters by adjustment of the effective length of the filters.
2. Prior Art
Arrangements of this type are known from the Swedish patent 9504324-6. These arrangements comprise filters that are made such, that the air flows through the ducts can be adjusted in correspondence to the ventilation need. The technique results in lower energy for the treatment of the supplied air flow by reducing the flow to the actual need. By using the filters for adjusting the air flows a ventilation system has been created that also is characterized by clean ducts without complicating and noise generating filter boxes, mechanical throttling devices and similar means. The characteristic of working noiseless of tested plants has excited a well-founded attention. It is a condition, however, that the adjustment of the filters can be carried out in a simple and exact manner, and that the adjustment means have a long life.